1. Field of the Invention
The present invention relates to a charging method, and more particularly to a method for charging portable electronic devices.
2. Description of Related Art
Currently, power supplies for portable electronic devices can be divided into two main types. One type of power supplies is external power supply. The other type of power supplies is battery. Generally, portable electronic devices are intended for use in the outdoors. Under such circumstance where there is no external power supply available to the electronic device, the only power source available to the portable electronic device is the battery installed in the device. In other words, batteries are the main power supply for portable electronic devices. Thus, the efficiency of a portable electronic device depends on whether its power supply is continuous and stable and whether its battery can be quickly and effectively charged.
At present, in most portable electronic devices, a charging process begins when the batteries are connected to an external power source and the charging process stops when the power of the battery is full. Nevertheless, batteries perform self-discharge. Therefore, the power capacity of a battery in a portable electronic device usually lowers after the battery has stopped charging for a period of time. Then, the battery in the portable electronic device is recharged.
FIG. 1 is a flowchart illustrating a conventional method for charging a battery of a portable electronic device. Referring to FIG. 1, the conventional method for charging the battery includes charge modes such as normal mode and trickle mode. When a portable electronic device is connected to a power source, it receives a control signal first (step S 10). Next, the portable electronic device decides a charge mode for charging the battery based on the received control signal (step S120), wherein the charge mode to be decided includes a normal mode (step S 130) and a trickle mode (step S140). Nonetheless, regardless of the charge mode being used, portable electronic devices detects whether the battery is full or not during the charging process (step S150).
If the battery is detected to be fully charged, the charging process is terminated (step S160). Then, the battery gradually discharges and its power is gradually lowered. Hence, the method returns to step S110 to reselect the charge mode for charging the battery. However, if the battery is detected to be partially charged, the battery is charged using the previously selected charge mode till the battery is full (step S170). After the battery is fully charged, the method likewise returns to step S110 and receives another control signal to decide the charge mode for charging the battery again. The processes of charging, discharging, and then recharging are repeated to ensure the battery stays fully charged. Nonetheless, repeating these processes increases the number of times for charging the battery and the capability of the battery for storing charges deteriorates as the number of times for charging the battery increases. As a result, the way for charging a battery using the conventional method shortens the life of the battery.
Further, if a user still operates the portable electronic device when the battery is being charged by an external power supply, conceivably most of the power provided by the power supply is used for the operation of the portable electronic device. As a result, the battery cannot be charged using maximum charging power so that the amount of time required to charge the battery is prolonged.